A dietitian reviews J. Lo and A-Rod's 10-day diet challenge

A few weeks ago, pop star and actress Jennifer Lopez and her husband, retired baseball sensation Alex Rodriguez, ate a whole lot of eggs, tuna and turkey. The meals were part of a 10-day no-sugar, no-carb challenge the duo undertook to apparently support their health. They publicly encouraged their fans and a few select celebs to do the same.

While this endeavor may seem healthy or at least harmless, as I registered dietitian, I don't see any point in this sort of short-lived deprivation.

Don't get me wrong: I think J.Lo is a superstar and, thanks to my three boys and Yankees fan husband, know A-Rod is incredible. But even though I love to dance and enjoy baseball, I'm not getting on stage anytime soon or critiquing anyone's pitch. I recommend Lopez and Rodriguez also stick to what they know best.

As Jason Riis, professor at the Wharton School at the University of Pennsylvania, puts it, "Some opinions are grounded in science and evidence, and others are grounded in emotion." And when it comes to celebrity diet plans like this one, followers are often swayed by their admiration for the star, not their common sense (or nutritionist's advice).

Let's take a closer look at the requirements of the Lopez-Rodriguez diet to see how well they do – and don't – match up to what I know to be good for health and well-being:

1. Cut out carbs.

The first rule of the couple's plan is no carbs. This hatred toward carbs is not exclusive to celebrities. In fact, I have rarely seen a food group as maligned as the category of carbohydrates. But carbs aren't the enemy. They simply get a bad rap because we love them in large portions and often eat them with unhealthy toppings (cheese and sausage on pizza, cream cheese on bagels, you get the idea), which can lead to weight gain.

Plus, when you make a blanket statement like "no carbs," that actually means no fruit and no veggies, not just no fettuccine and no French fries. And I think it's safe to assume that even J. Lo and A-Rod know that fruits and veggies are healthy; I guess they really meant to suggest only eliminating certain carbs.

What's more, eliminating carbs as an entire group means that you'd be ditching fiber, a nutrient the majority of us don't get enough of as it is, plus a wealth of the vitamins, minerals, antioxidants and phytonutrients that our bodies need each day.

I'm not done defending carbs yet: Studies show that carbs are the most readily available source of energy, which is especially important for people like Rodriguez and Lopez, who are very active. The Dietary Guidelines for Americans, based upon scientific evidence, suggests consuming around 45 to 65 percent of your calories from the carbohydrate group for optimal health.

Finally, ditching carbs typically means eating more protein than you need and consuming more fat, including fat from unhealthy sources. As A-Rod posted on Instagram, "No carbs + no sugar = lots of meat." That's not necessarily a good thing.

That's not to say all carbs are great for you all the time. I recommend considering cutting back or eliminating refined carbs that are ultra-processed, like your morning croissant or muffin and the pasta swimming in Alfredo sauce.

2. Cut out sugar.

Lopez and Rodriguez also said they shunned "sugar," basically pointing to cutting out indulgent snacks and desserts. While I can't fault them for aiming to cut out this source of unnecessary calories, it's likely they – or at least their followers – may not have succeeded. After all, sugar is the master of disguise, appearing on food labels under a variety of names other than sugar. Organic cane juice, high-fructose corn syrup and sucrose are just a few aliases that sugar uses.

It's also important to recognize that only one type of sugar – added sugar – is unhealthy. Natural sugars like those in fruit and dairy products needn't be on the do-not-eat list. And unfortunately, we won't clearly be able to distinguish between the two until new food labels finally get here, though some companies are already using them.

I'm not saying you shouldn't even try to cut sugar out of your diet, just understand it can be difficult – and not just because you have a sweet tooth. I recommend attempting to cut back if your diet contains an excessive amount of sugar or you're consuming more than 10 percent of your total calories from sugar, as recommended by the American Heart Association.

3. Do it for 10 days.

The third and final component of the no-carb, no-sugar challenge was its time frame: 10 days. That's good news in my book. Knowing that a challenge has a beginning and an end can push you to try something you otherwise would not have embarked upon, and gives you a chance to continue beyond the end date if you like the habit it created.

But 10 days isn't enough time to make a meaningful health impact if you don't continue on with some of your newfound habits. Even Rodriguez said that he couldn't wait to have pizza again once the 10 days were over. And that's the problem with challenges that are extreme: They rarely, if ever, last.

All that said, I'll give Lopez and Rodriguez credit for firing people up about their health and especially for including more physical activity in their days than many of us get in a year. In most cases, sticking to this plan won't be harmful – as long as you have an understanding of what carbohydrates are and which are best to include in your diet.

But there is a much more important message here: Each celebrity is a role model to millions of impressionable fans, many of whom are quite young. Like it or not, these stars often dictate the trends and habits of their followers, so encouraging healthy habits could have a lasting impact on the lives of so many people who'd benefit from help instead of hype. I hope these "influencers" put away their cleanses, cabbage soups and crazy concoctions and leave the nutrition advice to the pros.

Copyright 2019 U.S. News & World Report

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